Simple Event Correlator v2.8.2
From the website's blurb:
SEC is an event correlation tool for advanced event processing which can be harnessed for event log monitoring, for network and security management, for fraud detection, and for any other task which involves event correlation. Event correlation is a procedure where a stream of events is processed, in order to detect (and act on) certain event groups that occur within predefined time windows. Unlike many other event correlation products which are heavyweight solutions, SEC is a lightweight and platform-independent event correlator which runs as a single process. The user can start it as a daemon, employ it in shell pipelines, execute it interactively in a terminal, run many SEC processes simultaneously for different tasks, and use it in a wide variety of other ways.
SEC reads lines from files, named pipes, or standard input, matches the lines with patterns (like regular expressions or Perl subroutines) for recognizing input events, and correlates events according to the rules in its configuration file(s). SEC can produce output by executing external programs (e.g., snmptrap or mail), by writing to files, by sending data to TCP and UDP based servers, by calling precompiled Perl subroutines, etc.
I don't personally use or author this software, but it's Perl and is on my list of software to look in to.
Check it out, let me know what you think in the comments below.